Transient Pituitary Enlargement and Dysfunction due to Lymphocytic Hypophysitis

Abstract

The patient is a 23-year-old man, presenting with headache, central hypogonadism, and diffuse pituitary enlargement seen with magnetic resonance imaging (MRI). Because symptoms related to a pituitary mass were lacking, and after major etiologies of a pituitary fossa solid mass were ruled out with exception of an inflammatory pituitary disorder, we determined to follow the patient closely. Serum antipituitary antibodies, measured by an immunofluorescence technique using rodent pituitary cell lines GH3 and AtT-20, were strongly positive, suggesting lymphocytic hypophysitis. Three months after first consultation, a pituitary MRI showed a normal-sized gland. Prolactin deficiency was demonstrated using dynamic hormone testing. Antipituitary antibodies continued to be positive to GH3 and AtT-20 rodent pituitary cell lines. These findings remained until 20 months after presentation when pituitary function became normal. Antipituitary antibodies, however, remained positive until 48 months after presentation. Several points illustrated by our case are worthy of note. First, the diagnosis of lymphocytic hypophysitis was suspected and then confirmed without pituitary surgical exploration and biopsy. Second, in this case the disease was selflimited. Third, it suggests that pituitary autoantibodies can be a useful tool in diagnosing a noninvasive evaluation in suspected cases of lymphocytic hypophysitis.